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  Infusion fabric for molding large composite structuresUSPTO Application #: 20060089068Title: Infusion fabric for molding large composite structures Abstract: An infusion fabric includes a mat selected from a group consisting of continuous filament mat, direct chopped mat, direct continuous mat and combinations thereof and a woven roving or bonded reinforcement layer. The mat and woven roving reinforcement layer are stitched together. The continuous filament mat includes E-glass and/or ECR-glass fibers, a binder and a size. (end of abstract) Agent: Owens Corning - Granville, OH, US Inventors: David R. Hartman, Matthew W. Dunn USPTO Applicaton #: 20060089068 - Class: 442172000 (USPTO) Related Patent Categories: Fabric (woven, Knitted, Or Nonwoven Textile Or Cloth, Etc.), Coated Or Impregnated Woven, Knit, Or Nonwoven Fabric Which Is Not (a) Associated With Another Preformed Layer Or Fiber Layer Or, (b) With Respect To Woven And Knit, Characterized, Respectively, By A Particular Or Differential Weave Or Knit, Wherein The Coating Or Impregnation Is Neither A Foamed Material Nor A Free Metal Or Alloy Layer, Coated Or Impregnated Inorganic Fiber Fabric The Patent Description & Claims data below is from USPTO Patent Application 20060089068. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION [0001] This invention relates generally to an infusion fabric that may be molded into large composite structures as well as to a novel continuous filament mat and a novel binder. BACKGROUND OF THE INVENTION [0002] Reinforcement fabrics made from fibrous materials formed into woven, knitted and non-woven material, are well known in the art. Yarns of glass, carbon and aramid are typically formed into fabrics, and a plurality of layers of fabric are stacked and cut into dry fabric kits or performs. The preforms are then infused or impregnated with a resin binder and cured to form a rigid composite. [0003] Typically a glass reinforced fibrous mat is preformed and then placed in a mold for molding into a fiber-reinforced article. Glass fiber-reinforcement mats are used in situations where a desired strength is necessary, such as in truck fenders, auto chassis or bus components and the like. For example, layers of the continuous strand mat and layers of unidirectional or multidirectional reinforcement material are fabricated separately. These layers are individually placed in a set of preformed screens, which generally consist of an upper screen and a lower screen. The upper and lower screens are moved together in order to conform the layers to the shape of the preformed screens. The layers are thus shaped into what is known as a preform. The preform is then placed in a mold and injected with a suitable resinous material to make the fiber reinforced article. [0004] U.S. patent application Ser. No. 10/674,987, filed on Sep. 30, 2003, (OC Case No. 25253) owned by the assignee of the present invention, discloses a crimp-free infusible reinforcement fabric. The unidirectional fabric has small size tows spaced between large size tows. The "channels" that are formed from the small tows between the larger tows permit faster resin infusion and increased productivity. [0005] The present invention relates to an improved infusion fabric that better optimizes kitting, preforming, conformability to tooling, resin infusion rate, consolidation thickness, surface aesthetics, and composite structural performance in a range of closed molding processes including VIP, RTM and RTM Lite or VARTM processes. This represents the full range of composite closed molding processes used by marine, wind, construction, transportation and industrial customers. In addition, the present invention relates to a novel continuous filament mat and binder useful in making that improved infusion fabric mat. SUMMARY OF THE INVENTION [0006] The infusion fabric comprises a mat selected from a group consisting of continuous filament mat, direct chopped mat, direct continuous mat and combinations thereof along with a woven or bonded reinforcement layer. In one possible embodiment the mat and woven roving or bonded reinforcement layer are stitched together. [0007] More specifically describing the invention, the mat is constructed from a material selected from a group consisting of glass fibers, carbon fibers, graphite fibers, vitreous carbon fibers, non-graphite carbon fibers, boron monolithic graphite fibers, boron monolithic non-graphite carbon fibers, silicone, aramid fibers, ceramic fibers, thermoplastic polymer fibers and mixtures thereof. Natural fibers such as, for example, cotton, kenaf, sisal and jute may also be used alone or in combination with any of the above. The woven roving reinforcement layer may also be constructed from the same list of materials. [0008] Typically the woven roving reinforcement layer has an areal weight of between about 8 to about 60 oz/sq. yd. Further, the woven roving reinforcement layer is selected from a group consisting of plain, twill and satin style. The woven roving reinforcement layer can include multiple parallel tows at least two tows of which have differing yields so as to form spaced channels. Typically a first tow of the two tows has a yield A of between about 750 to about 2500 yds/lb. and a second tow of said two tows has a yield B of between about 52 to about 450 yds/lb. [0009] In accordance with still another possible embodiment of the present invention the infusion fabric may include a surfacing mat. The mat is sandwiched between the surfacing mat and the woven roving reinforcement layer. [0010] In accordance with one particular embodiment of the present invention, the mat of the infusion fabric is a continuous filament mat including E-glass fibers and/or ECR-glass fibers, a binder and a size. More specifically, this continuous filament mat includes between about 80 and about 99 weight percent glass fibers, between about 1 and about 20 weight percent binder and between about 0.01 and about 1 weight percent size on the fiber. The glass fibers are provided as glass filament bundles. The glass filament bundles include between about 20 to about 140 filaments per bundle. Each filament has a mean diameter of between about 11 to about 26 microns. The bundle diameter is between about 0.127 to about 3.175 mm. The loop formation ratio ranges from about 2.0 to about 8.0. [0011] The binder is a polyester or an epoxy compatible binder such as epoxy resin and epoxy novolak. The polyester binder is ground to a particle size of between about 25 to about 200 mm. The binder also includes talc and benzoyl peroxide. More specifically, the binder includes between about 92.5 and about 99.9 weight percent polyester, between about 0.01 and about 5 weight percent talc and between about 0.1 and about 2.5 weight percent benzoyl peroxide. [0012] Still further, the continuous filament mat has a degree of cure expressed as acetone extractables of between about 50 and about 100 percent. More typically, the continuous filament mat has a degree of cure expressed as acetone extractables of between about 60 and about 90 percent. [0013] In accordance with yet another aspect of the present invention, a continuous filament mat is provided. The continuous filament mat comprises E-glass fibers and/or ECR-glass fibers, a binder and a size. The continuous filament mat includes between about 90 and about 98 weight percent E-glass or ECR-glass fibers, between about 2 and about 10 weight percent binder and between about 0.1 and about 1.0 weight percent size on the fiber. The glass fibers are provided as glass filament bundles. The glass filament bundles include between about 20 to about 140 filaments per bundle. Each filament has a mean diameter of between about 11 and about 26 microns. The bundle diameter is between about 0.127 and about 3.175 mm. The loop formation ratio ranges from about 2.0 to about 8.0. The cure, measured as acetone extractables, is between about 50 and about 100 percent and more typically between about 60 and about 90 percent. [0014] In a particularly useful embodiment, the continuous filament mat includes E-glass or ECR-glass fiber bundles having between about 44 to about 50 filaments per bundle or loop strand. The bundle diameter mean is about 0.3048 mm and the range is from about 0.127 to about 1.27 mm. The strand to mat architecture or loop formation ratio is between about 6.0 and 6.6. [0015] In accordance with still another aspect of the present invention, a binder is provided for preparing a glass fiber mat. The binder comprises between about 95 and about 99.8 weight percent polyester, between about 0.05 and about 3 weight percent talc and between about 0.2 and about 2 weight percent benzoyl peroxide. The polyester binder is ground to a particle size of between about 25 to about 200 mm. The polyester is based upon ethylene glycol and fumaric acid. [0016] In the following description there is shown and described several different embodiments of this invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain certain principles of the invention. In the drawings: [0018] FIG. 1 is a partially sectional perspective view of one possible embodiment of the infusion fabric of the present invention; [0019] FIG. 1a is a full cross sectional view of the infusion fabric illustrated in FIG. 1; [0020] FIG. 2 is a partially sectional perspective view of another possible embodiment of the infusion fabric of the present invention; and Continue reading... Full patent description for Infusion fabric for molding large composite structures Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Infusion fabric for molding large composite structures patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Infusion fabric for molding large composite structures or other areas of interest. ### Previous Patent Application: Composite fabric with controlled release of functional chemicals Next Patent Application: Simulated rip stop fabrics Industry Class: Fabric (woven, knitted, or nonwoven textile or cloth, etc.) ### FreshPatents.com Support Thank you for viewing the Infusion fabric for molding large composite structures patent info. 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